Question

Mr. T. undergoes CABG, and the left internal mammary artery (LIMA) is implanted to the left main coronary artery. Why is the LIMA used? What are the postoperative priorities?

Answer 1

Here a study is compared with the coronary and conduit disease progression in the left anterior descending coronary artery treated with coronary artery bypass grafting using the left internal mammary artery which is commonly known as LIMA, is compared with percutaneous coronary intervention with bare metal stent, termed as BMS and drug eluting stent referred as DES.

The above study describes that the Percutaneous coronary intervention, (PCI), with stent deployment and coronary artery bypass grafting (CABG), have evolved as the standard modes of treatment in the management of coronary artery disease (CAD). But their effectiveness is limited by the recurrence of symptoms caused by the graft or stent failure or by progression of atherosclerosis in the native coronary vessels.

Now to describe the matter in details with the factors associated with long term event free survival post of coronary revascularization which includes the patient's pre-procedural status and comorbidities, conduit patency, and the downstream atherosclerosis disease progression in the native coronary. The unique biological properties and histological characteristics of IMA conduits used in CABG have been proposed as main factors contributing to the reduced susceptibility to atherosclerosis and superior long‐term graft patency of IMA.

PCI with coronary stenting is currently the most common treatment in patients. Here sufficient evidence illustrates the association between catheter based coronary interventions and arterial injury, which leads to endothelial dysfunction. During stenting, endothelial cells are partially or completely destroyed along with medial wall injury and stretching, which promotes activation of platelets, and thrombus formation accompanied by inflammatory reaction.

As you very well know that the downstream coronary patency is important to maintain myocardial perfusion and prevent recurrence of symptoms and repeat interventions. Progression of downstream CAD, increase the rates of repeat intervention which might, decrease long term survival rates of patients undergoing coronary revascularization.

The purpose of this study is to compare the effect of CABG with left LIMA to the LAD coronary artery versus PCI using either bare metal stent or drug eluting stent on downstream coronary atherosclerosis. This disease in progression of multivessel, CAD patients undergoing isolated primary coronary revascularization. We hypothesized that LIMA is associated with a lesser degree of downstream coronary and conduit disease progression compared with percutaneous coronary stents.